A key product of both Forest Inventory and Analysis (FIA)
of the USDA Forest Service and the Natural Resources Inventory
(NRI) of the Natural Resources Conservation Service is a scientific
data base that should be defensible in court. Multiple imputation
procedures (MIPs) have been proposed both for missing value estimation
and prediction of non-remeasured cells in annualized forest inventories
such as the Southern Annual Forest Inventory System (SAFIS).
MIPs generate clean-looking data bases that are easily used but
hide a serious weakness: under different assumptions made by
reasonable people, very different data bases and conclusions
can be generated. A MIP is an interesting idea for prediction
but should only be used for analyses by users, not for filling
in data in a public data base. Simple illustrations are given
to make our points.

To maintain a defensible data base, FIA and NRI should only
provide algorithms to facilitate user-generated data for prediction
of non-remeasured cells. Users, not FIA and NRI, should be responsible
for generating data bases that utilize these algorithms or other
algorithms of their choosing, incorporating assumptions that
they are willing to make. But they should be encouraged to work
with FIA and NRI personnel in utilizing such algorithms.